1.創建 Dynamic Web Project ,Dynamic Web module version選擇3.0

2.在自動生成 的web.xml配置，增加 metadata-complete="false"

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <javaee:web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 3 xmlns="http://Java.sun.com/xml/ns/javaee"
 4 xmlns:javaee="http://java.sun.com/xml/ns/javaee"
 
 
 5 xmlns:web="http://java.sun.com/xml/ns/javaee" 
 6 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
 7  metadata-complete="false" version="3.0">
 8   <javaee:display-name></javaee:display-name>
 9   <javaee:welcome-file-list>
10     <javaee:welcome-file
 
>index.html</javaee:welcome-file>
11   </javaee:welcome-file-list>
12 </javaee:web-app>

3.創建監聽類，在監聽類頭部增加 註解 @WebListener

package com.xhkj.listener;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
@WebListener
 

public class MyServletContextListener implements ServletContextListener {
	 @Override
	    public void contextDestroyed(ServletContextEvent sce) {
	        System.out.println("===========================MyServletContextListener銷毀");
	    }

	    @Override
	    public void contextInitialized(ServletContextEvent sce) {
	        System.out.println("===========================MyServletContextListener初始化");
	        System.out.println(sce.getServletContext().getServerInfo());
	    }

}

4.啟動tomcat服務。打印結果如下

5 註意事項，每次修改配置或者java代碼後，要重新編譯，否則不起作用

@WebListener 註解方式實現監聽